This invention relates to an improved construction for a fibrous layer used in vehicle trim panels.
In the prior art fibrous layers are utilized in vehicle trim panels. As one example, vehicle headliners have been proposed which have layers made up of a plurality of fibers joined together at intersections. One proposal is a combination of binder and non-binder fibers. A percentage of fibers are formed with a binder covering, and the remainder of the fibers are formed without the binder. The layer is constructed of a combination of these fibers. When the layer is heated, the binder melts providing an adhesive to secure the two types of fibers together.
The fibrous layers to date have utilized two basic constructions. In a first construction, a plurality of fibers are randomly mixed. The fibers are then needled through the thickness of the layer. Needling provides structure to the overall fiber layer.
In a second basic type of construction, a so-called "flat mat" construction is utilized wherein the fibers are laid down in angled paths extending from one lateral side of the layer to the opposed lateral side. The fibers are deposited from a known fiber depositing structure such as a nozzle. The large angled paths of the nozzle results in the fibers building up to form the layer. With either type prior art structures, there has typically been a general constant amount of material at any one location throughout the layer.
It is desirable in trim applications, and in particular in headliner applications to have different densities and thicknesses at different locations in the layer. As an example, it may be desirable to have a thinner high density portion at one portion of the headliner. It is also sometimes desired to have thicker portions at the outer periphery of a headliner. In general, the prior art has required that if it is desired to have a high density portion at one location on the layer, the entirety of the layer must be have sufficient mass to achieve the same high density. It has been somewhat difficult to have variable mass or variable thickness in the amount of material deposited into the layers with the prior art approaches. This has resulted in undesirable large material requirements.